Waec Model Questions Vol1 2018 Chemistry Question 5
Practice essay / theory question 5 from the 2018 Waec Model Questions Vol1 Chemistry examination. This question covers Stoichiometry .
A 20.0 g mixture of calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃) contains 12.0 g of CaCO₃ and 8.0 g of MgCO₃. The mixture is reacted with excess hydrochloric acid according to the equations: CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O MgCO₃ + 2HCl → MgCl₂ + CO₂ + H₂O (a) Calculate the theoretical mass of carbon dioxide gas that can be evolved when the mixture reacts completely. (b) The CO₂ produced is collected over water at 25 °C and a total pressure of 760 mmHg, giving a volume of 5.00 L. Determine the percent yield of CO₂ based on the theoretical mass obtained in part (a). (c) Explain why excess HCl is required for the reaction and discuss two practical considerations when collecting the gas over water.
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This is Waec Model Questions Vol1 2018 Chemistry Question 5. It is one of the essay questions from the 2018 Waec Model Questions Vol1 Chemistry examination.
The question covers Stoichiometry .
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